Semi-analytic forecasts for JWST – IV. Implications for cosmic reionization and LyC escape fraction
Author
Yung, L Y AaronSomerville, Rachel S
Finkelstein, Steven L
Popping, Gergö
Davé, Romeel

Venkatesan, Aparna
Behroozi, Peter
Ferguson, Harry C
Affiliation
Univ Arizona, Steward ObservIssue Date
2020-06-20Keywords
galaxies: evolutiongalaxies: formation
galaxies: high-redshifts
galaxies: star formation
dark ages, reionization, first stars
cosmology: theory
Metadata
Show full item recordPublisher
OXFORD UNIV PRESSCitation
Yung, L. A., Somerville, R. S., Finkelstein, S. L., Popping, G., Davé, R., Venkatesan, A., ... & Ferguson, H. C. (2020). Semi-analytic forecasts for JWST–IV. Implications for cosmic reionization and LyC escape fraction. Monthly Notices of the Royal Astronomical Society, 496(4), 4574-4592.Rights
© 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Galaxies forming in low-mass haloes are thought to be primarily responsible for reionizing the Universe during the first billion years after the big bang. Yet, these haloes are extremely inefficient at forming stars in the nearby Universe. In thiswork, we address this apparent tension, and ask whether a physically motivated model of galaxy formation that reproduces the observed abundance of faint galaxies in the nearby Universe is also consistent with available observational constraints on the reionization history. By interfacing the Santa Cruz semi-analytic model for galaxy formation with an analytic reionization model, we constructed a computationally efficient pipeline that connects 'ground-level' galaxy formation physics to 'top-level' cosmological-scale observables. Based on photometric properties of the galaxy populations predicted up to z = 15, we compute the reionization history of intergalactic hydrogen. We quantify the three degenerate quantities that influence the total ionizing photon budget, including the abundance of galaxies, the intrinsic production rate of ionizing photons, and the LyC escape fraction. We explore covariances between these quantities using a Markov chain Monte Carlo method. We find that our locally calibrated model is consistent with all currently available constraints on the reionization history, under reasonable assumptions about the LyC escape fraction. We quantify the fraction of ionizing photons produced by galaxies of different luminosities and find that the galaxies expected to be detected in James Webb Space Telescope Near-Infrared Camera (NIRCam) wide and deep surveys are responsible for producing similar to 40-80 per cent of ionizing photons throughout the Epoch of Reionization. All results presented in this work are available at https://www.simonsfoundation.org/semi-analytic-forecasts-for-jwst/.ISSN
0035-8711EISSN
1365-2966Version
Final published versionae974a485f413a2113503eed53cd6c53
10.1093/mnras/staa1800